Stretching device, particularly applicable to thin phonographic disks



Nov. 29, 1932. A. A. PENTEADO STRETCI'IING DEVICE, PARTICULARLY APPLICABLE TO THIN PHONOGRAPHIC DISKS Original Filed July 8, 1929 l atented Nov. 29, 1932 sires STATE AnMAnno ALvAnEs rnn'rnnno, or rams-rennet:

STRETCHIN'G nnvron, rARrrcn AnLY .VAVPPLICAZBIJE fro rrrm PHONOGRAPHIC DISKS Original application filed July 3, 1929, Serial No. 376,698, and in France June 12,1929. Divided. and

- this application filed August 18, 1930. SeriaI NO. 476,223.

The resent inventionrelates to a stretch-V in g ClGVlCG which allows thin disks, and more. particularly those which form thesub ect of .7

specification Ser. No. 376,698 filed July 8, ,5 1929, of whichthis isa division, to be rigidly gripping device such as ascrewv which passes through lugs which form part of the d1sk,

andthe inner disk has on its upper surface a groove in whicha cuttmg memberengages in order to effect cuttlng the disk after recording has been efiected. V

One formof construction of'the invention is illustrated in the annexed drawing, 1n

wh1ch:

2 the disk stretchingdevice,

Fig. 2 is a section on theline 22 of 1.

Figs. 3 and dare sectional side views on the line 33 of Fig. 1, showing the manner in which the diskis placed on the stretching device.

Fig.5 is a sectional view on a larger scale,

showing howcutting of the disk is effected, and 1 r 6 showsthe manner of using a disk on which recording is being effected.

The disk a, which is preferably of viscose or the material known under the registered trade-markas Cellophane as described in of slightly larger diameter than the ring 6, and this is cut away at din order that it maybe gripped on theperiphery of the ring I; v

'is passed through the sheet intoa small cirpresent applicant, dated 14th November,

by means of a screw c which engages lugs 0',c oft heringc. j V

When the latter is forced on to the'ring b thedisk a is perfectly stretched, as shown in Fig.4,- owing to the fact that the over- 5o, held in place, andalso to be readily out. This lapping edgeof the disk is bent-down by means of the ring 0.

The screw 6 is then tightened to hold the disk in its stretched position, and a hole is pierced in the centre of the disk, recording being finally effected on both surfaces.

After the recording hasbeen effected, and

after the disk has been thoroughly dried it is cut by means of a cutting member f which cular groove 6 formed on the uppersurface of the ring 5, and which is caused to follow V j the said circular groove. Fig. 1 is a plan view, partly in section, of

The disk a thus formed, and 'which has j been subjected to recording on one or both apparatus of the type forming the subject of French Patent N o. 57 3,131 in the name of the The diska is held in place on the turntable of the gramophoneby means, for example, of a ring it which is placed above the 7 disk on the, said turn table 71. i

It is obvious that modifications may be introduced into the process and apparatus descrlbed above without departing'from the spirit of theinvention. For example, the

application of the stretching device is not limited to disks having a cellulose base, but

maybe utilized in connection with thin sheets of any composition or material in connection with direct phonographic recording. What I claim is Stretching device for thin phonograpliie disks comprising a ring for receiving the softened disk provided with a circumferential groove in one of itsplane annularfaces and .a ring of slightly larger diameter adapted to be forced on the other ring so as to engage the overlapping edge of the disk, I

whereby the disk is stretched and the recording efi'ected thereon, the disk then dried, and

cut by any cutting member inserted in the circuinferential groove.

In testimony. whereof I specification. I ARMANDO ALVARES PENTEADO.

have signed this 

